Hello there,
I would like to build a current source based on the Howland current source. I read an interesting article about the composite amplifier and i thought might be a good idea to built a composite howland current source to improve the properties (noise, offset voltage, bandwidth, etc.)
To provide an output current of 3A the power source has an input voltage of 30V. For this reason, I have the resistance R7 set with 10 Ohm. I would use the OPA541 for OPV U2, because it can deliver an output current of 5A. This Amplifier has only the task of providing the power and the OPV U1 is supposed to take over the actual function, right?
My questions are:
- Is a composite howland current source a good idea, in consideration of the stability?
- How exactly do I need to dimensioned the OPV U2? Which parameters are as important?
- Does the OPV U2 need a supply voltage of at least 30V or can I also adjust this smaller, so still the Function is guaranteed?
I hope someone can help me and sorry for my bad english
